Japan Journal of Food Engineering, Vol. 9, No. 1, pp. 9-20, Mar. 2008 Recent Progress in Food Science and Engineering Review Quantitative Risk Assessment for Korean Style Menu Items: A Case Study on the Exposure Assessment of Saengchae (A Korean Radish Salad) Seung Ju LEE•õ and Aeri PARK Department of Food Science and Technology, Dongguk University 26, 3-ga, Pil-dong, Chung-gu, Seoul, 100-715, Korea Today, Korean style dishes are being globalized, and with such a trend, it should be ensured that they can be safe from foodborne contamination. In this study, QRA, which is a quantitative technique to predict contamination levels and to perform sensitivity and scenario analyses , was performed in order to achieve better safety management for Korean style menu preparations. First, the hygienic conditions of Korean style dishes were surveyed, showing that these foods would not be safe if managed improperly. Saengchae, which was one of the dishes, proved vulnerable to pathogen contamination, and was selected for the case study. As a result, the hazard factor was determined as Staphylococcus aureus, and the hygienic conditions in the restaurant used for the case study were considered safe from food contamination. Through sensitivity analysis, the CCP in the preparation procedure was determined as the storage step. Through scenario analysis, the CL of the resultant CCP was estimated as a storage temperature lower than 15•Ž , when stored for 3-5 hours. In conclusion, we demonstrated that QRA, known as a versatile solution in quantitative analysis, can be applied successfully to aid conventional HACCP for the safety management of Korean style menu items. Therefore, this study provides an example of a quantitative approach for more extensive cases in the safety management of Korean style dishes. Key words: quantitative risk assessment, Korean style menu items, exposure assessment, Saengchae (a Korean radish salad) 1. Introduction mandatory application of HACCP was assigned to several food items, while it was only optional before that time Since the 1980s, there have been large changes in [6,7]. There is ongoing research to expand the application Korea in terms of its population, jobs available to women, of HACCP in restaurant business [8-11]. At the present improvements in economic status, etc. In addition, the time, food safety issues are more popular than in the past, foodservice industry has become more competitive, espe- but in restaurants, there is still a need to address food cially since the 1990s [1,2] . In the years 1993, 1999, and safety concerns. Therefore, a better understanding of food 2003, the numbers of restaurants in Korea were 361173, safety in Korean restaurants is required. 412166, and 505241, respectively. Korean style restaurants Korean style menus, consisting of a few main dishes accounted for 60.77% of all restaurants in 1993, and are concomitant with many side dishes, are prepared in sever- still rising in number [3-5]. However, most of them are al ways. In general, the preparation methods encompass small-scale restaurants, and they are usually managed non-heat, heat and post-heat cooking. The main dishes under poor conditions for various aspects, including food primarily include items prepared by heating methods, but safety. In Korea, HACCP (hazard analysis critical control rarely non-heat or post-heat cooking methods. point) was introduced in 1995 to prevent food poisoning, Fortunately, the target dishes for safety management were with food safety laws strictly established. In 2000, HACCP found to be non-heat or post-heat prepared dishes was applied to almost all food items in Korea. In 2003, the [13,14]. Since non-heat prepared items do not undergo a heating process, they are more likely to be contaminated. The sources of contamination include already contaminat- (Received 29 Dec. 2007: accepted 11 Feb. 2008) Fax: +82-2-2260-3372, E-mail: [email protected] ed ingredients, and cross-contamination through cooking 10 Seung Ju LEE and Aeri PARK utensils or the kitchen environment, including food han- cations [12], Saengchae falls under non-heat dishes, that dlers. Thus, more safety cautions are required for non- are generally more likely to be contaminated. QRA is com- heat prepared items, from handling of the raw ingredients posed of hazard identification, exposure assessment, to serving the finished dish. In particular, temperature dose-response assessment, and risk characterization [15]. control was found to be the most critical aspect because In this case study, QRA was limited to hazard identifica- kitchens are usually at 5•`60•Ž, which is known as the tion and exposure assessment. The exposure assessment danger zone for microbial growth [ 12,15,i]. is a key step to predict the contamination levels for the fin- Several techniques or systems for food safety manage- ished menu items. The routes for contamination, which ment have been developed, such as HACCP, SSOP (sanita- are the occasions of exposure, were identified, and then tion standard operating procedure), and GMPs (good the hygienic conditions of each occasion were analyzed in manufacturing practices) [7,16-19]. Nonetheless, the inci- terms of contamination levels and management status. dence of food poisoning has continued to rise [ii]. Currently, HACCP is the most popular system for safety 2.2.1 Identification of occasions of exposure management, but in its practice, the identification of CCPs The contamination routes include the purchased raw (critical control points) and estimation of CLs (critical lim- ingredients, preparing of the dish, and storing and serving its) are usually difficult, and these are of great importance the finished dish (Fig. 1). The preparation methods of in HACCP. The reason for difficulty is that CCP identifica- three typical Korean restaurants located in Seoul, as well tion and CL estimation are performed in long-term cycles as several technical reports, were surveyed [12,14] . In this and are based on professional consultation, safety manage- case study, the occasions of exposure were limited to cut- ment status at the locations, and surveys of past records of ting, mixing, and storing before serving. Therefore, pur- food poisoning occurrences. Therefore, QRA (quantitative chase, inspection, trimming, and washing were not consid- risk assessment), a supplementary technique to HACCP, ered in the exposure assessment. was introduced to quantitatively identify CCPs and esti- mate CLs [15,20-23] . Moreover, in QRA, actual contamina- 2.2.2 Sampling and microbial assay of tion levels and process conditions with variability and Staphylococcus aureus uncertainty can be substituted into mathematical functions The ingredients at 10.25 g each, were collected with through Monte Carlo simulation [24,25]. sterile tongs, and put into a sterile vinyl bag with 0.1% buff- In this study, QRA was performed to improve the safety ered peptone water (BPW) in an amount 9-fold greater management of a Korean style dish. Exposure assessment than the sample weight. Next, the sample was processed in QRA was performed to quantitatively identify the CCP by a model PUL 100E Pulsifier (Microgen Bioproducts and estimate the CL, in which the target dish was chosen Ltd, UK) . Then, 1 ml of the extract, which was transmitted as Saengchae (a Korean radish salad). Also, to a test tube with sterile water, was stepwise diluted 10 Staphylococcus aureus (which was recognized as a hazard) times. Also, the cooking utensils such as the knife, cutting levels of the served dish, were predicted under certain board, mixing bowl, and storage container were swabbed hygienic conditions of the Korean style restaurants used with a special 3MTM e. swab, within a surface area of 10 •~ 10 in this case study. cm2 (length •~ width). This sample was subsequently treat- ed in the same manner as the ingredients. 2. Materials and Methods The properly diluted sample solutions of 1 ml were streaked on Baird Parker RPF agar (bioMerieuxðF sa, 2.1 Hygienic characteristics of Korean style France). The Staphylococcus aureus colonies were counted dishes 24.48 hr after incubation at 35•Ž. The hygienic characteristics of Korean style menu items were examined via literature survey, in terms of the han- 2.2.3 Monte Carlo simulation dling of raw ingredients, preparation methods, serving, Monte Carlo simulation is known to be an effective and etc. practical tool to handle data with uncertainty and variabili- ty, and it can estimate contamination levels according to 2.2 Case study for exposure assessment in QRA exposures. In this study, the exposure occasions included Saengchae (a Korean radish salad) was selected for the the already existing contamination of the washed ingredi- assessment. According to official food preparation classifi- ents, cross contamination from cutting and mixing, and Quantitative risk assessment for Korean style menu items 11 Fig. 1 Flow chart of steps in the preparation procedure of Saengchae (a Korean radish salad) . Exposure assessment in this case study covered only the steps from cutting to storing before serving . Dotted rectangle indicates the steps considered in the case study. microbial growth during storing before serving. As the than just a trend, it became a CL for the CCP. The above first step in the Monte Carlo simulation , the contamination operations were executed with the options of Latin hyper- levels as well as working conditions at each step were cube sampling and 10000 iterations. expressed in appropriate distribution functions . Second, cross contamination levels were added, and microbial 3. Results and Discussion growth was calculated according to Gompertz equation [15,27]. Lastly, the Monte Carlo simulation was performed 3.1 Hygienic characteristics of Korean style with @RISK 4.0 software (Plisade Inc, 2000) to predict the dishes contamination level of the finished Saengchae . The menu items served in restaurants were surveyed , The calculation procedure first decided the probability and consisted largely of three styles: Korean, Japanese , functions for the input data of the microbial level as well as and Western, in which Korean style dishes were found to the other variables such as temperature and food prepara- be the most popular.